Making clothing that doesn't look like it came from MS Paint

I know how to use the clothing templates and stuff and I have a good grasp of general art techniques and use of TheGIMP (PS users, don't ignore this thread: if you give instructions for Photoshop, I can probably translate them to TheGIMP easily enough!).

So how the heck do you get your stuff to look so realistic?

I know about photosourcing and I can do it for flat textures but getting a photo to fit onto the clothing template is a bit beyond my comprihention.

I also need to make some non-photorealistic stuff for some anime avatars I've been sitting on for a while. The pleated skirts I made for them look passable if you don't look too closely...but I tried making boots for one of them and they absolutely sucked.

Doesn't help that I only have the mouse to draw with either (I will probably invest in a tablet somewhere down the road, but untill then...).

Any advice you folks could hand out would be great.

There's some good tips in this thread /109/57/33062/1.html

Yes there are some good tips in that thread and also, don't despair, I have a tablet gathering dust on my desk LOL. I started with a mouse and I've stuck with a mouse, I just couldn't get the hang of using a pen at all. I learned very quickly that the tablet doesn't make things easier for everyone. Good luck!